Transit and city form are a chicken-and-egg problem: without good transit, things (houses, offices, tourist attractions) will scatter all over the map, which makes it difficult and expensive to provide good transit. "Who Framed Roger Rabbit?" is obviously a dramatization, but it has some basis in reality: the initial sprawl of Los Angeles was driven by streetcars, not automobiles, and even today many of the freeways follow old Pacific Electric routes.

Enough of that old "things clustered around old transit lines" infrastructure remains to make at least a limited view of Los Angeles possible without a car: Wilshire or Santa Monica boulevards through the Westside, for instance, are pretty obviously lined with cool things to do. That might be why it's the focus of a few Transit Adventures itineraries from Experience LA (the local tourist board). Similarly, UAL's in-flight magazine recently ran a feature article on LA by Metrorail.

There's also this NYT piece on Santa Monica and Venice largely without a car. The Big Blue Bus heads from LAX's bus terminal right through Venice and into SM.